fix for etcd-io#19066 Print warnings when deprecated options are conf…

…igured in config file

Signed-off-by: mansoora <[email protected]>

server/config/config.go

@@ -216,6 +216,13 @@ type ServerConfig struct {
 // VerifyBootstrap sanity-checks the initial config for bootstrap case
 // and returns an error for things that should never happen.
 func (c *ServerConfig) VerifyBootstrap() error {
+	// Print deprecation warnings first
+	if warnings := c.checkDeprecatedOptions(); len(warnings) > 0 {
+		for _, warning := range warnings {
+			c.Logger.Warn(warning)
+		}
+	}
+
 	if err := c.hasLocalMember(); err != nil {
 		return err
 	}
@@ -234,8 +241,13 @@ func (c *ServerConfig) VerifyBootstrap() error {
 // VerifyJoinExisting sanity-checks the initial config for join existing cluster
 // case and returns an error for things that should never happen.
 func (c *ServerConfig) VerifyJoinExisting() error {
-	// The member has announced its peer urls to the cluster before starting; no need to
-	// set the configuration again.
+	// Print deprecation warnings first
+	if warnings := c.checkDeprecatedOptions(); len(warnings) > 0 {
+		for _, warning := range warnings {
+			c.Logger.Warn(warning)
+		}
+	}
+
 	if err := c.hasLocalMember(); err != nil {
 		return err
 	}
@@ -365,3 +377,21 @@ func (c *ServerConfig) BackendPath() string { return datadir.ToBackendFileName(c
 func (c *ServerConfig) MaxRequestBytesWithOverhead() uint {
 	return c.MaxRequestBytes + grpcOverheadBytes
 }
+
+// Add this new function to check deprecated options
+func (c *ServerConfig) checkDeprecatedOptions() []string {
+	var warnings []string
+
+	// Check for deprecated configurations
+	if c.ForceNewCluster {
+		warnings = append(warnings, "WARNING: 'force-new-cluster' option is deprecated and will be removed in future versions")
+	}
+
+	if c.V2Deprecation == "" {
+		warnings = append(warnings, "WARNING: v2 API is deprecated and will be decommissioned in etcd v3.6")
+	}
+
+	// Add more deprecated option checks as needed
+
+	return warnings
+}